The present invention relates to housings for fragile electrical components, and particularly to a protective housing incorporating a flexibly attached mounting plate.
Magnetic reed switches are frequently used to control the state of electrical position monitoring and control circuitry by sensing the proximity or absence of an actuating magnet which may be carried on a door, window frame, or a part of a mechanism whose position is being monitored. Commonly, the amount of power used in such sensing and control circuitry is quite small, permitting the reliable use of magnetic reed switches which are quite small and are encapsulated in glass to protect the magnetic reed contacts from the corrosive effects of the atmosphere.
Because of the fragility of the small glass capsules containing the magnetic reed switches, it has been common in the past to use a fairly large housing to mount the magnetic reed switches. This has previously been necessary to avoid damaging the glass switch capsule during tightening of mounting screws or while driving tacks used to mount such switch housings. Especially when such a switch housing is mounted on a surface which is not completely flat, the stress caused by installing the fasteners used to mount the switch housing can cause damage to the magnetic reed switch.
Frequently, in order to provide required stiffness, such prior art switch housings are made of metal, which provides ample protection for such a reed switch. Such protection is frequently unnecessary, however, and the use of such metal housings is therefore unnecessarily expensive.
Because of their large size, such prior art switch housings are visually very obvious, a disadvantage in the use of such housings in physical security circuits for monitoring the position of doors, windows, and the like. Because they take up a considerable amount of space, such prior art switch housings are disadvantageous, as well, in many industrial equipment position sensing applications.
Previously known switch housings have been attached to surfaces by means of exposed screws or nails. These are, perhaps, necessary for security, but when exposed to view they detract from a pleasant appearance. While in some applications a small encapsulated magnetic reed switch can be securely mounted by the use of adhesive materials, some protection for the glass capsule containing the switch is still necessary.
What is desired, therefore, is a small protective housing for a small electrical component such as a magnetic reed switch, including provisions for attaching the switch housing to a surface by secure means such as screws or nails without leaving such fasteners unattractively exposed to view. Such a housing should be capable of being mounted without danger of damaging the fragile electrical component contained in the housing as a result of over tightening mounting screws or as a result of shock incurred during the driving of tacks and brads. It is also desirable to provide a protective housing which may be mounted by means other than such secure fasteners where desired.